Physics for Poets By William Lama Ph.D.
Physics for Poets
By William Lama Ph.D.
Image above: The Quantum Poet, Symmetry Magazine
The 2020 Nobel Prize in physics was awarded to UCLA astronomer Andrea Ghez for her “discovery of a supermassive compact object (a Black Hole) at the centre of our galaxy.”
Andrea Ghez, UCLA Astronomy professor. Photo by Elena Zhukova, U. California
Now, you can’t see a black hole since its immense gravity sucks up everything in its vicinity, including light. But you can observe the effect of the black hole gravity on stars in orbit around it. That’s what Ghez did.
Stars orbiting the Milky Way center. UCLA Keck Observatory
The time to complete an orbit for one of these stars is as much as 50 years. Thus, to record the positions over time took many years of telescope time (and infinite patience). The results are remarkable, clearly showing stars orbiting an invisible supermassive object, the black hole.
Physics for the math challenged
That was the type of science story I liked to use when I taught a college course called “Physics for Poets” many moons ago. The text of the same name described the course intent, “to convey some sense of physics as a human activity, in the profound conviction that it is neither as incomprehensible nor as removed from the general culture as is commonly thought.”
I taught the course for several years and was in for some surprises. First, the student body was mostly female, composed of nursing, dental hygiene and other medical types. They were required to take a physical science course and this one was in their wheelhouse. It was nearly devoid of math, leading to my second surprise. I had been teaching physics for engineers where math was used as a crutch to “explain” difficult concepts. Physics for Poets was harder to teach since I had to do without my crutch. My third surprise was how much I enjoyed the experience, largely because the students did too.
The course is still being taught in many colleges. Here is a 2020 testimonial by a Dartmouth College student. https://admissions.dartmouth.edu/follow/blog/catherine-parnell/physics-poets
“Welcome to physics for poets! The class I didn't realize how much I needed, until I was in it. I love it. We talk about the history of science and trace its origins way back to the days of the early classics, when humans first started thinking about the universe. Our study takes us all the way up until our present day understanding of quantum theory and the space-time continuum. We integrate science with the importance of philosophy, and we talk about the relationship between religion and science.”
Just a bit of math
Physics for Poets dealt with mathematics in the simplest way. For example, when talking about Galileo’s observation that all bodies (apples or bowling balls) fall with the same acceleration of g = 32 feet per second squared, it was easy to see that after one second the speed of the object (apple or bowling ball) would be 32 ft/sec and after 2 sec it would be 64 ft/sec and so on. If dropped at the same time from the top of a building the apple and bowling ball would hit the ground at the same time.
But at what time and at what speed? Here enters the only equation. The distance (S) is related to the time (t) by S = (½) g t^2. To complete the problem let the height of the building be S = 1600 ft. Plugging S and g into the equation gives 1600 = 16 t^2 which yields t = 10 sec. Returning to the speed progression 32, 64, 96,… we obtain 320 ft/sec when they hit the ground. QED.
Unless the air is filled with mayo.
It’s been said that physics and poetry are both capable of revealing profound truths about the universe and our place in it.
Energy
Energy was one of the most interesting topics. Power is related to energy. Like how many horses power the 1966 Mustang that I almost got (PV Pulse, Oct 2020) and what is horsepower anyway?
Energy is a ubiquitous physical quantity encompassing mechanical, electrical, chemical, nuclear and other types. A Mustang moving 60 mph has a lot of mechanical kinetic energy. Energy can be used to do work and power is the rate of change of energy or the rate of doing work (just like the rate of change of distance is speed). A horsepower was defined a long time ago as the amount of work done by a “standard horse” in a specified time. Now that “standard horse” must have had a name, so they should have named the unit after her. “Sally” would be nice.
Today one horsepower is defined as 760 watts. Most home appliances use kilowatts of power and we pay for the energy measured in kilowatt-hours (kWh). The monthly electrical usage for a typical PV home in the summer might be 1200 kWh, costing $300 at a rate $0.25/kWh.
Humans in the US use about 12,000 kWh of energy per person in a year. Our energy use produces about 16 tons of carbon dioxide emissions per person per year. Lately that has been a concern since carbon dioxide is a cause of global warming. In California the level of concern is so great that Gov. Gavin Newsom issued an executive order to ban gasoline powered cars by 2035, leading to some creative solutions.
The Babylon Bee
“General Motors is making waves after a surprise unveiling of a line of exciting new California-compliant vehicles. Officials at the company revealed its latest innovation for the West Coast: the 2021 HORSE AND BUGGY, with an organic, intelligent engine capable of listening to your voice commands, and even reproducing other engines.”
https://babylonbee.com/news/california-to-replace-cars-with-new-greener-horse-drawn-carriages
However, back when I taught Physics for Poets the opposite was happening. People were freaking out about global cooling and the coming ice age.
Politicians in the 1970s were worried about energy availability, particularly oil, and President Carter recommended turning the thermostat down in the winter and wearing a sweater. At college that’s what we did. Since carbon dioxide produces warming US car companies happily increased the size of engines.
Since water vapor in the atmosphere is even better at warming, I proposed a solution using orbiting vaporizers, a fleet of supertankers spraying water vapor into the atmosphere. My patent application was denied. I can’t imagine why.
By the turn of the century everything had flipped and people were freaking out about global warming. Message to my students: The temperature goes up, the temperature goes down. Live with it.
Teaching science and doing science are different occupations. I liked to tell a story about the Nobel Prize winning physicist Richard Feynman who defined the scientific method this way.
First, you guess. Then you compute the consequences of your guess. Then you compare those consequences with the evidence from observations or experiments. If your guess disagrees with experiment, it’s wrong. That simple statement is the key to science. It does not make a difference how beautiful the guess is, how smart you are, or who you are … it’s wrong.
“Some scientists fall so in love with their guesses that they fail to test them against evidence. They just compute the consequences and stop there. Mathematical models are elaborate, formal guesses, and there has been a disturbing tendency in recent years to describe their output with words like data, result or outcome. They are nothing of the sort.”
Matt Ridley, “What the pandemic has taught us about science,” The Wall Street Journal
Domesticating physics
It turns out that Physics for Poets was not the first time a physics course was designed for the math challenged. Around the turn of the 20th century schools and colleges began offering courses for housewives to encourage them to learn about, try, and buy new technologies such as vacuum cleaners. Household physics courses tried to mold female students into “modern” housewives who no longer feared but welcomed technological innovation.
I’ll save that interesting story for a future issue of Palos Verdes Pulse.
Dr. William Lama has a PhD in physics from the University of Rochester. Taught physics in college and worked at Xerox as a principle scientist and engineering manager. Upon retiring, joined the PVIC docents; served on the board of the RPV Council of Home Owners Associations; served as a PV Library trustee for eight years; served on the PV school district Measure M oversight committee; was president of the Malaga Cove Homeowner's Association. Writes about science, technology and politics, mostly for his friends.
email: wlama@outlook.com